Structure-stability correlations for imine formation in aqueous solution

Imine formation between 25 aldehydes and 13 amines in aqueous solution in the pH range 7-11 was studied by H-1 NMR spectroscopy. A three-parameter linear equation correlating logarithms of imine formation constants with pK(a) and HOMO energies of amines and LUMO energies of aldehydes is proposed. In view of the widespread occurrence of imine-forming processes in both chemistry and biology, the data presented are of significance for physical organic chemistry and of particular interest for dynamic combinatorial chemistry. Copyright (c) 2005 John Wiley & Sons, Ltd.